diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h
index 1079e214fe85..7c9ec953c519 100644
--- a/arch/riscv/include/asm/sbi.h
+++ b/arch/riscv/include/asm/sbi.h
@@ -33,6 +33,7 @@ enum sbi_ext_id {
 	SBI_EXT_PMU = 0x504D55,
 	SBI_EXT_DBCN = 0x4442434E,
 	SBI_EXT_STA = 0x535441,
+	SBI_EXT_NACL = 0x4E41434C,
 
 	/* Experimentals extensions must lie within this range */
 	SBI_EXT_EXPERIMENTAL_START = 0x08000000,
@@ -279,6 +280,125 @@ struct sbi_sta_struct {
 
 #define SBI_SHMEM_DISABLE		-1
 
+enum sbi_ext_nacl_fid {
+	SBI_EXT_NACL_PROBE_FEATURE = 0x0,
+	SBI_EXT_NACL_SET_SHMEM = 0x1,
+	SBI_EXT_NACL_SYNC_CSR = 0x2,
+	SBI_EXT_NACL_SYNC_HFENCE = 0x3,
+	SBI_EXT_NACL_SYNC_SRET = 0x4,
+};
+
+enum sbi_ext_nacl_feature {
+	SBI_NACL_FEAT_SYNC_CSR = 0x0,
+	SBI_NACL_FEAT_SYNC_HFENCE = 0x1,
+	SBI_NACL_FEAT_SYNC_SRET = 0x2,
+	SBI_NACL_FEAT_AUTOSWAP_CSR = 0x3,
+};
+
+#define SBI_NACL_SHMEM_ADDR_SHIFT	12
+#define SBI_NACL_SHMEM_SCRATCH_OFFSET	0x0000
+#define SBI_NACL_SHMEM_SCRATCH_SIZE	0x1000
+#define SBI_NACL_SHMEM_SRET_OFFSET	0x0000
+#define SBI_NACL_SHMEM_SRET_SIZE	0x0200
+#define SBI_NACL_SHMEM_AUTOSWAP_OFFSET	(SBI_NACL_SHMEM_SRET_OFFSET + \
+					 SBI_NACL_SHMEM_SRET_SIZE)
+#define SBI_NACL_SHMEM_AUTOSWAP_SIZE	0x0080
+#define SBI_NACL_SHMEM_UNUSED_OFFSET	(SBI_NACL_SHMEM_AUTOSWAP_OFFSET + \
+					 SBI_NACL_SHMEM_AUTOSWAP_SIZE)
+#define SBI_NACL_SHMEM_UNUSED_SIZE	0x0580
+#define SBI_NACL_SHMEM_HFENCE_OFFSET	(SBI_NACL_SHMEM_UNUSED_OFFSET + \
+					 SBI_NACL_SHMEM_UNUSED_SIZE)
+#define SBI_NACL_SHMEM_HFENCE_SIZE	0x0780
+#define SBI_NACL_SHMEM_DBITMAP_OFFSET	(SBI_NACL_SHMEM_HFENCE_OFFSET + \
+					 SBI_NACL_SHMEM_HFENCE_SIZE)
+#define SBI_NACL_SHMEM_DBITMAP_SIZE	0x0080
+#define SBI_NACL_SHMEM_CSR_OFFSET	(SBI_NACL_SHMEM_DBITMAP_OFFSET + \
+					 SBI_NACL_SHMEM_DBITMAP_SIZE)
+#define SBI_NACL_SHMEM_CSR_SIZE		((__riscv_xlen / 8) * 1024)
+#define SBI_NACL_SHMEM_SIZE		(SBI_NACL_SHMEM_CSR_OFFSET + \
+					 SBI_NACL_SHMEM_CSR_SIZE)
+
+#define SBI_NACL_SHMEM_CSR_INDEX(__csr_num)	\
+		((((__csr_num) & 0xc00) >> 2) | ((__csr_num) & 0xff))
+
+#define SBI_NACL_SHMEM_HFENCE_ENTRY_SZ		((__riscv_xlen / 8) * 4)
+#define SBI_NACL_SHMEM_HFENCE_ENTRY_MAX		\
+		(SBI_NACL_SHMEM_HFENCE_SIZE /	\
+		 SBI_NACL_SHMEM_HFENCE_ENTRY_SZ)
+#define SBI_NACL_SHMEM_HFENCE_ENTRY(__num)	\
+		(SBI_NACL_SHMEM_HFENCE_OFFSET +	\
+		 (__num) * SBI_NACL_SHMEM_HFENCE_ENTRY_SZ)
+#define SBI_NACL_SHMEM_HFENCE_ENTRY_CONFIG(__num)	\
+		SBI_NACL_SHMEM_HFENCE_ENTRY(__num)
+#define SBI_NACL_SHMEM_HFENCE_ENTRY_PNUM(__num)\
+		(SBI_NACL_SHMEM_HFENCE_ENTRY(__num) + (__riscv_xlen / 8))
+#define SBI_NACL_SHMEM_HFENCE_ENTRY_PCOUNT(__num)\
+		(SBI_NACL_SHMEM_HFENCE_ENTRY(__num) + \
+		 ((__riscv_xlen / 8) * 3))
+
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_PEND_BITS	1
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_PEND_SHIFT	\
+		(__riscv_xlen - SBI_NACL_SHMEM_HFENCE_CONFIG_PEND_BITS)
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_PEND_MASK	\
+		((1UL << SBI_NACL_SHMEM_HFENCE_CONFIG_PEND_BITS) - 1)
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_PEND		\
+		(SBI_NACL_SHMEM_HFENCE_CONFIG_PEND_MASK << \
+		 SBI_NACL_SHMEM_HFENCE_CONFIG_PEND_SHIFT)
+
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_RSVD1_BITS	3
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_RSVD1_SHIFT \
+		(SBI_NACL_SHMEM_HFENCE_CONFIG_PEND_SHIFT - \
+		 SBI_NACL_SHMEM_HFENCE_CONFIG_RSVD1_BITS)
+
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_TYPE_BITS	4
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_TYPE_SHIFT	\
+		(SBI_NACL_SHMEM_HFENCE_CONFIG_RSVD1_SHIFT - \
+		 SBI_NACL_SHMEM_HFENCE_CONFIG_TYPE_BITS)
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_TYPE_MASK	\
+		((1UL << SBI_NACL_SHMEM_HFENCE_CONFIG_TYPE_BITS) - 1)
+
+#define SBI_NACL_SHMEM_HFENCE_TYPE_GVMA		0x0
+#define SBI_NACL_SHMEM_HFENCE_TYPE_GVMA_ALL	0x1
+#define SBI_NACL_SHMEM_HFENCE_TYPE_GVMA_VMID	0x2
+#define SBI_NACL_SHMEM_HFENCE_TYPE_GVMA_VMID_ALL 0x3
+#define SBI_NACL_SHMEM_HFENCE_TYPE_VVMA		0x4
+#define SBI_NACL_SHMEM_HFENCE_TYPE_VVMA_ALL	0x5
+#define SBI_NACL_SHMEM_HFENCE_TYPE_VVMA_ASID	0x6
+#define SBI_NACL_SHMEM_HFENCE_TYPE_VVMA_ASID_ALL 0x7
+
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_RSVD2_BITS	1
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_RSVD2_SHIFT \
+		(SBI_NACL_SHMEM_HFENCE_CONFIG_TYPE_SHIFT - \
+		 SBI_NACL_SHMEM_HFENCE_CONFIG_RSVD2_BITS)
+
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_ORDER_BITS	7
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_ORDER_SHIFT \
+		(SBI_NACL_SHMEM_HFENCE_CONFIG_RSVD2_SHIFT - \
+		 SBI_NACL_SHMEM_HFENCE_CONFIG_ORDER_BITS)
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_ORDER_MASK	\
+		((1UL << SBI_NACL_SHMEM_HFENCE_CONFIG_ORDER_BITS) - 1)
+#define SBI_NACL_SHMEM_HFENCE_ORDER_BASE	12
+
+#if __riscv_xlen == 32
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_ASID_BITS	9
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_VMID_BITS	7
+#else
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_ASID_BITS	16
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_VMID_BITS	14
+#endif
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_VMID_SHIFT	\
+				SBI_NACL_SHMEM_HFENCE_CONFIG_ASID_BITS
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_ASID_MASK	\
+		((1UL << SBI_NACL_SHMEM_HFENCE_CONFIG_ASID_BITS) - 1)
+#define SBI_NACL_SHMEM_HFENCE_CONFIG_VMID_MASK	\
+		((1UL << SBI_NACL_SHMEM_HFENCE_CONFIG_VMID_BITS) - 1)
+
+#define SBI_NACL_SHMEM_AUTOSWAP_FLAG_HSTATUS	BIT(0)
+#define SBI_NACL_SHMEM_AUTOSWAP_HSTATUS		((__riscv_xlen / 8) * 1)
+
+#define SBI_NACL_SHMEM_SRET_X(__i)		((__riscv_xlen / 8) * (__i))
+#define SBI_NACL_SHMEM_SRET_X_LAST		31
+
 /* SBI spec version fields */
 #define SBI_SPEC_VERSION_DEFAULT	0x1
 #define SBI_SPEC_VERSION_MAJOR_SHIFT	24
